1. The Field of the Invention
This application concerns a system and a process for measuring the degree of cure of fiberglass.
2. State of the Art
Fiberglass contains glass fibers and binder which includes water and resin. The purpose of the binder is to hold the glass fibers together. In some cases the term fiberglass can be used to mean only the glass fibers; however, as used herein the term fiberglass means the mixture of glass fibers and binder.
During the manufacture of fiberglass, binder is mixed with glass fibers and the mixture is cured by heating. During the curing process the binder becomes relatively solid and cohesive and is instrumental in bonding the glass fibers to each other. During the manufacturing process it is important to know the degree to which the fiberglass is cured so that the minimum amount of heat energy can be applied to the fiberglass while insuring that sufficient heat energy is provided to result in adequate bonding of the glass fibers.
U.S. Pat. No. 4,363,968, the inventors of which are McGowan et al., teaches a system for measuring the degree of cure of fiberglass. The device taught in the patent uses infrared radiation and x-ray or gamma ray radiation to measure the degree of cure of fiberglass. In building and operating a device to measure the degree of cure, one must utilize the proper wavelength of infrared radiation in order to obtain correct results. However, the patent fails to teach the proper wavelength of infrared radiation which should be used to measure the degree of cure.
A further shortcoming of the McGowan patent is that x-rays or gamma rays must be used in conjunction with infrared radiation in order to determine the degree of cure. An x-ray or gamma ray source is different from an infrared radiation source and therefore the device utilizes two sources of radiation which is a more complicated and error prone system than a single source of radiation.